We have continued the pioneering of vibrational infrared and Raman spectroscopic imaging techniques, at both the microscopic and macroscopic levels, by advancing the methodology to the mid-infrared spectral region. This spectral interval (2.5micromoles to 25micromoles or 4000 cm-1 to 400 cm-1) provides a wealth of vibrational spectroscopic probes for the analysis of systems extending from the biochemical and biophysical disciplines to the analytical chemistry areas. In particular, we have developed and refined a powerful new mid-infrared spectroscopic chemical imaging technique which combines step-scan Fourier transform (Fl) Michelson interferometry with indium antimonide (InSb) focal-plane array (FPA) detection. This first time coupling of an infrared focal-plane army detector to an interferometer provides an instrumental multiplex/multichannel advantage, an enormous enhancement for obtaining spectral information. Specifically, the multiple detector elements enable all pixels to be collected simultaneously, while the interferometer portion of the system allows all the spectral frequencies to be measured concurrently. With this method of mid-infrared spectroscopic imaging, the fidelity of the generated spectral images is limited by only the number of pixels defining the FPA detector. Also, only several seconds of detector staring time are required for spectral image acquisition. We believe that this novel, high-definition technique represents the future of infrared chemical imaging analysis, a new discipline within the chemical, biological and material sciences. In addition, this step-scan interferometric approach achieves the ability to perform high-definition mid-infrared imaging in near real-time. Studies have involved the chemical imaging of tissues related to neurotoxicity problems and samples of brain slices of animals treated with a variety of drugs.